Shock absorber for the suspension arrangements of vehicles



March 17, 1925. 1,529,878

. G. H. E. DE RAM SHOCK ABSORBER FOR'THE SUSPENSION ARRANGEMENTS 'OF VEHICLES Filed Nov. 20, 1922 25 Hg. 4 I

. 'lNVi-INTOR having P. O.

.for the Suspension Patented Mar. 17, 1925.-

' UNITED STATES TENT OFFICE.

cannons HENRI ERNEST m RAM, OF/BOULOGNE sun SEINE, FRANCE.

SHOCK ABSORBER F03 THE SU SPENSION ARRAIJGEMENTS OF VEHICLES.

Application filed November 20, 1922. Serial No. 602,297.

To aZZ whomitwmy concern:

Be it known that -I, GEORGES HENRI ER- NEs'r on RAM. engineer, citizen of the French Republic, residing at Boulogne sur Seine,

Department of the Seine, in France, and I address 22 Rue de Silly, in the said city, have inv ented certain new and useful Improvements in Shock- Absorbers Arrangements of Vehicles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention has reference to shock absorbers or damping devices for the suspension arrangements of vehicles and more especially for those arrangements in which the flexibility of the springs is somewhat slight; that is to say arrangements 1n which the movements of the springs, when below a certain speed, require to-be braked T or damped on expansion so as to avoid rebounds. WVhen the vehicle is travelling above the said speed the rise of the axle must, on the contrary, be braked or damped in order to ensure a good adhesion of the wheels to the ground. The shock absorber or clamping device according to this invention, whilst realizing these; conditions, is of the so-called liquid type and is characterized furthermore, by an actibn which varies with the speed. a

In the accompanying drawings there are illustrated general forms of shock absorbers or damping devices according to this invention.

In said drawingsz- I Fig. 1 is a longitudinal section taken through one form of shock absorber embodying my invention.

Fig. 2 is a similar view taken through a modified form.

Fig. 3 is a similar fragmentary view taken through another modified form, and

Fig. 4 is a view similar to Fig. 3, taken through a still further modification.

Onreferring to Figure 1 it will be seen i that the arrangement comprises a piston 1 the rod 2 ofwhich is connected in a suitable manner to the axle. This piston moves ina cylinder 3 including valves4 and 5 at the right hand end and valves 6 and 7 near the other end of the said cylinder; suitable springs regulate the lifts of these valves. Ports 1 0 and 11 permit communication by means of a conduit 8 betwcenthe two opposite sides of the piston. At 9 there is a cylinderin which moves a free piston :9; this cylinder forms an air chamber. The method of operation is as follows: The device is so adjusted that a rising movement of the axle causes a displacement of the piston in the direction of the arrow.- If the displacement is not very violent the flow of the liquid contained in the shock absorber will take place through the ports 11 and 10 and even through the valve 4 under certain 0011- ditcilons, the output of this valve be ng limite Upon its return the piston will be braked, as the liquid in front of the pistoncan flow off only through the port 10. This port, which has the form of a nozzle, presents as a matter of fact a greater'resistance to the passage of-theliquid on the return of the piston, than it does when the piston moves to the right in the direction ofthe arrow.

Vfhen the shocks are more violent and the displacements of the piston more rapid,

it will no-longer be possible for the liquid to flow off through the channels indicated above, the aperture being too small. The fluid will then lift the braking valve 4 and displace the'piston 9, thus compressing the air in the cylinder 9. A vacuum will consebraked, the liquid running off through. the

orifice 10; if, on the contrary, the speed is high then the valve 7 will be lifted and the 'return f the axle will take place rapidly. ,For this purpose the valve v7 is so regulated .querrtly be formed at the left handside ofas not to be lifted under the action of the suspension spring alone.

In the shock absorber. shown in Figure 2, the operation is slightly different, the air cylinder 9 being done away with, the device in this case is entirely filled with liquid.

The shock absorber shown in this figure comprises a cylinder and a piston 13 fitted thereto and connected to the axle l2.by a suitable transmission gear. Three valves are provided in the cylinders'at 14:, 15 and 19, and ports 18, 19 and 20 are provided in the front of the cylinder, the object of which will be hereinafter; described. The

small piston'valve 19, closing the port 20,

is rigidly secured to a small piston 18',

slidably mounted between the ports 18 and 19. Conduits 16 and '17 establish communication between the two sides .of the piston 13. The action of thisshock absorber is as follows: The displacement of the piston 13 in thedirection of the arrow, due to the lift .be pushed forward a greater or lesser distance by the liquid according to the speed at which the liquid flows,

extent, uncovering the port or opening 20.

The return will be made through this opening, the conduit 16 and the valve 15. Cons uently it is the position of the piston va ve 19 which regulates the size of the outlet .through the port 20. This piston valve is connected to the small hydraulic brake formed'by the piston 18 which can move freely from left to right asthe liquid enters direct into its cylinder through the port 19, but upon the return this port is blocked by a flap 21 of suitable type and the piston valve 19 only moves slowly back to its closing position.

The braking of the rising movements of the axle is, therefore, eifected by the valve 14 and thus increases together with the speed; the braking of the expansion of the spring, on the contrary, decreases in proportion as the-speeditxcreasesfthe-section of the port 20 being progressively increased.

Figure 3 shows a modification of the arrangement described with reference to Figure 2. In this case the valve 19 and the piston 18 control a' valve 21 Which communicates through the conduit 23 with the right hand side of the spherical piston 13:

the conduit 17 communicates withthis same part through the port 22. The piston 18 eing of stamped leather the .small valve of the conduit 19, Figure 2, may be done away with. The valve 2l"could-, of course, be re placed by anyother type than that indicated.

Figure 4 shows an auto-regulating device like that described in applicationjSeria-l Nr, 598,146 filed October 31st, 1922, and in this arrangement it is the 'action0f thepressure reigning in the left hand part of the cylinder which determines the regulation of the return port. A small valve 24 brakes the movement-of the piston 25 made in one with the valve 26'.

Claims: 1. A shock absorber for vehicles comprising a cylinder containing a fluid .and a piston reciprocable in said cylinder and operthus, to a certain ea ers able by movement of the. axle of the vehicle, a conduit extending longitudinally of the cylinder, anda chamber atnoneiend of the latter, apertures establishing lcomi'nunication between the cylinder and conduit on both sides of the piston, and valved'ports controlling communication between said cylin- Iderand said chamber, substantially as described' U 2. Ashock absorber for Vehicles comprising a cylinder containing a fluid and a pistonreciprocable in said cylinder and operable by movement of the-axle of the vehicle, a conduit extending longitudinally of the cylinder, and a chamber at one end of the latter, apertures establishing communicm tion between the'cylinder and conduit on both sides of the piston. valved ports controlling communication between said cylinder and said chamber, and means for compressing air insaid chamberlby the reciprocation of the piston, and for utilizing said compressed air to effect the return movement of the piston, substantially as described. c

3. A shock absorber for vehicles comprising a cylinder containing a fluid and a pis ton reciprocable therein by movement of the axle of the vehicle, a partition extending longitudinally of the cylinder and forming a conduit and a chamber at one end of the cylinder, and valve-controlled ports establishing communicationbetween said cylinder, on one side'of said piston, and between a said chamber and said cylinder, on the other side of said piston, substantially as described.

4. A shock absorber for vehicles comprising a cylinder containing a fluid and a pie ton reciprocable therein-by movement of the axle of the vehicle, in 'combination'withvalved portscommunicatingwith the cylinder on one side of the piston, and with means whereby reciprocation of/the piston,

compresses air on the other side thereof, sub stantially as described.

5. A shdck absorber for vehicles comprising a cylinder containing a fluid and a piston reciprocable therein by movement of the.

axle of the vehicle, in combination with valved ports communicating with the cylin der on .one side of the piston, and with means whereby reciprocation ot' the'piston compresses air on the other side thereof, and means for utilizing said compressed air to effect the return reciprocation of the piston,

substantially as described.

In testimony whereof I aifix my signature.

GEORGES llENRl ERNEST de RAM. 

